1. Scale Drawings and Models

2. Warm-Up The blueprint for a bedroom is given below.
How many units wide is the room?
The actual width of the room is 18 feet. Write a ratio comparing the drawing width to the actual width.
Simplify the ratio you found and compare it to the scale shown at the bottom of the drawing.
width
closet
= 2 feet

3. Record the definition in your math journal.
Scale Drawing
Record the definition in your math journal.
A scale drawing or a scale model is used to represent an object that is too large or too small to be drawn or built at actual size.

4. Scale
The scale is the ratio of a length on a drawing or model to its actual length.
1 inch = 4 feet 1 inch represents an actual distance of 4 feet.

5. Example of Scale Size

6. Scale Model of a Map of Toronto

7. “I am wanting to go from Pantages Theatre to the Four Seasons Hotel where I am staying. Can I walk or should I catch a cab?”

8. We can estimate using the scale
About
2 1/2 miles

9. Scale Versus Scale Factor
Scale does not have to have the same unit, so the units must be written
Scale Factor has the same units so they are not written

10. So, the scale is 1 inch = 13 1/3 feet
Find the Scale
A passenger car of a model train is 6 inches long. If the actual car is 80 feet long, what is the scale of the model?
Let x to represent the actual length of the train. Write and solve a proportion to find the scale of the model.
Length of Train Scale
model 6 in. 1 in. model
actual ft x ft actual
6 * x = 80 * 1
6x = 80
x = 13 1/3
So, the scale is 1 inch = 13 1/3 feet =

11. Example Problem
The model Ms. Wagliardo made of the building she designed was 16 inches tall. If the actual building is to be 64 feet tall, what is the scale of her model?

12. Find the Scale Factor 1:160 1 in = 13 1/3 feet 1 foot = 12 inches
13 1/3 feet = ____ inches
Scale Factor then is:
_______
160
1:160

13. Example Problem
Knowing that the scale of her model is 1 inch equals 4 feet, what is the scale factor?
1 inch equals 4 feet
1 foot = 12 inches
4 feet = ________ inches
Scale Factor :

14. Applications of Scale Models and Similar Figures
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Activity 1:
Applications of Scale Models and Similar Figures